/////////////////////////////////////////////////////////////////////////////// | |
/// \file pop_back.hpp | |
/// Proto callables Fusion pop_back | |
// | |
// Copyright 2010 Eric Niebler. Distributed under the Boost | |
// Software License, Version 1.0. (See accompanying file | |
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
#ifndef BOOST_PROTO_FUNCTIONAL_FUSION_POP_BACK_HPP_EAN_11_27_2010 | |
#define BOOST_PROTO_FUNCTIONAL_FUSION_POP_BACK_HPP_EAN_11_27_2010 | |
#include <boost/fusion/include/begin.hpp> | |
#include <boost/fusion/include/end.hpp> | |
#include <boost/fusion/include/prior.hpp> | |
#include <boost/fusion/include/pop_back.hpp> | |
#include <boost/proto/proto_fwd.hpp> | |
namespace boost { namespace proto { namespace functional | |
{ | |
/// \brief A PolymorphicFunctionObject type that invokes the | |
/// \c fusion::pop_back() algorithm on its argument. | |
/// | |
/// A PolymorphicFunctionObject type that invokes the | |
/// \c fusion::pop_back() algorithm on its argument. | |
struct pop_back | |
{ | |
BOOST_PROTO_CALLABLE() | |
template<typename Sig> | |
struct result; | |
template<typename This, typename Seq> | |
struct result<This(Seq)> | |
: result<This(Seq const &)> | |
{}; | |
template<typename This, typename Seq> | |
struct result<This(Seq &)> | |
: fusion::result_of::pop_back<Seq> | |
{}; | |
template<typename Seq> | |
typename fusion::result_of::pop_back<Seq>::type | |
operator ()(Seq &seq) const | |
{ | |
// Work around a const-correctness issue in Fusion | |
typedef typename fusion::result_of::pop_back<Seq>::type result_type; | |
return result_type(fusion::begin(seq), fusion::prior(fusion::end(seq))); | |
} | |
template<typename Seq> | |
typename fusion::result_of::pop_back<Seq const>::type | |
operator ()(Seq const &seq) const | |
{ | |
return fusion::pop_back(seq); | |
} | |
}; | |
}}} | |
#endif |